package hdoj;

import java.util.Scanner;

// 2201 熊猫阿波的故事
public class RandomSeat {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		while(scanner.hasNext()){
			int n = scanner.nextInt();
			int m = scanner.nextInt();
			double res = 1.0 / n;
			//不知道为什么，System.out.printf("%.2f\n", res); Persentation Error
			System.out.printf("%.2f", res);
			System.out.println();
		}
		scanner.close();
	}
}
